A rainfall may be classified as acidic if its pH value is less or equal to________________?
(A) 6
(B) 7
(C) 5
(D) 6.5
If is the diameter of upper circular portion, the overall depth of a standard egg shaped section, is___________________?
(A) D
(B) 1.25 D
(C) 1.5 D
(D) 1.75 D
The recommended detention period for grit chambers is_______________?
(A) 1 minute
(B) 2 minutes
(C) 3 minutes
(D) 5 minutes
For sewer mains of 0.5 to 1 m diameter, the ratio of maximum daily sewage flow to the average daily sewage flow is assumed__________________?
(A) 1.5
(B) 2.0
(C) 2.5
(D) 3.0
In Chezy’s formula V = C rs for calculating the velocity of flow in circular sewer of diameter running full, the value of hydraulic mean radius is_______________?
(A) D
(B) D /2
(C) D/3
(D) D/4
The design period of sewage treatment works in normally_________________?
(A) 5 – 10 years
(B) 15 – 20 years
(C) 30 – 40 years
(D) 40 – 50 years
Oxidation process results in the formation of___________________?
(A) Carbon dioxide
(B) Nitrates
(C) Sulphates
(D) All the above
The sewerage system consists of______________________?
(A) House sewer
(B) Lateral sewer
(C) Branch sewer
(D) All of these
The minimum diameter of sewer to be adopted is_________________?
(A) 10 cm
(B) 12.5 cm
(C) 15 cm
(D) 25 cm
The porosity of sediments in sewer pipes, is usually taken as___________________?
(A) 0.010
(B) 0.011
(C) 0.012
(D) 0.013